Citing safety reasons, the Russian traffic police impounded two buses bound for Yerevan on Thursday two days after eight Armenians were killed and over 40 others wounded in an accident 200 kilometers south of Moscow.

The RIA Novosti news agency quoted a spokesman for Moscow’s police department, Andrey Galiakberov, as saying that both vehicles, apparently owned by Armenian firms, were found to be in a poor technical condition. Their four Armenian drivers will be fined as a result, he said.

“Exploitation of these buses in the territory of Russia will be banned until the elimination of all detected problems,” added Galiakberov.

The buses were reportedly full of passengers travelling from Moscow to Yerevan when they were stopped by the Russian police. Their owners were not immediately known.

The crashed bus belonged to an Armenian transport company, King Deluxe. Its owner has ruled out the possibility of a technical malfunction. According to the Regnum news agency, Russia’s Deputy Interior Minister Aleksandr Savenko said on Thursday that the Chinese-made bus overturned on a highway in the Tula region because its driver fell asleep at the wheel.

Armenian and Russian law-enforcement authorities are currently investigating the accident. They have announced no official conclusions yet.

In what appears to be a related development, the Armenian government announced on Thursday plans to toughen licensing requirements for transport firms providing bus services in and outside Armenia. The Ministry of Transport and Communications said it has put forward a bill stipulating that such firms can be allowed to operate only on a competitive basis.

First Deputy Transport Minister Artur Arakelian claimed that the bill was drafted months before the Tula accident.

Under existing Armenian laws and regulations, bus companies transporting people on a non-regular basis do not need to receive government licenses and undergo special technical inspections.